Xcode多部分请求

我想上传一张带有标题、说明和GPS数据的图像。我正在尝试以下操作并返回一个错误：

NSData *imageData = UIImageJPEGRepresentation(image, 90);
NSString *urlString = @"http://geopg.de/backend/PictureUpload";

NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setURL:[NSURL URLWithString:urlString]];
[request setHTTPMethod:@"POST"];

NSString *boundary = [NSString stringWithString:@"---------------------------14737809831466499882746641449"];
NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@", boundary];
[request addValue:contentType forHTTPHeaderField:@"Content-Type"];

NSMutableData *postBody = [NSMutableData data];

//title part
[postBody appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[[NSString stringWithString:@"Content-Disposition: form-data; name=\"title\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[self.chosenImage.imgTitle dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];

//desc part
[postBody appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[[NSString stringWithString:@"Content-Disposition: form-data; name=\"desc\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[self.chosenImage.imgDescription dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];

//latitude part
[postBody appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"latitude\"%d\r\n\r\n", value2] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];

//longitude part
[postBody appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"longitude\"@d\r\n\r\n", value2] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];

//media part

[postBody appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[[NSString stringWithString:@"Content-Disposition: form-data; name=\"file\"; filename=\".jpg\"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[[NSString stringWithString:@"Content-Type: application/octet-stream\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
[postBody appendData:[NSData dataWithData:imageData]];
[postBody appendData:[[NSString stringWithFormat:@"\r\n--%@--\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];

//add body to post
[request setHTTPBody:postBody];

我试着只上传没有标题，描述的图片。。。而且效果很好。我认为问题在于我如何构建我的帖子主体。我希望有人能帮助我。

/category Annncio-----Text

//文件------图像--------

---

你能修正你的缩进并添加一些注释或解释，说明你的代码是如何解决OP的问题的吗？我认为问题是当发布文件或文本时，字符串中的/r/n太多了。你可以在我的代码中看到差异。

    [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"category\"\r\n\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[@"90" dataUsingEncoding:NSUTF8StringEncoding]];
    [body appendData:[@"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];

        [body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
        NSString *insiemeDati =[NSString stringWithFormat:@"%@%@%@",@"Content-Disposition: form-data; name=\"userfile\";filename=",NOmeImmagine,@";\r\n"];
        [body appendData:[insiemeDati dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:[@"Content-Type: application/octet-stream\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
        [body appendData:[NSData dataWithData:ImmagineData]];
        [body appendData:[@"\r\n" dataUsingEncoding:NSUTF8StringEncoding]];